Who is ‘Source D’? The man said to be behind the Trump-Russia dossier’s most salacious claim.

In June, a Belarusan American businessman who goes by the name Sergei Millian shared some tantalizing claims about Donald Trump.

Trump had a long-standing relationship with Russian officials, Millian told an associate, and those officials were now feeding Trump damaging information about his Democratic opponent, Hillary Clinton. Millian said that the information provided to Trump had been “very helpful.”

Unbeknownst to Millian, however, his conversation was not confidential. His associate passed on what he had heard to a former British intelligence officer who had been hired by Trump’s political opponents to gather information about the Republican’s ties to Russia.

The allegations by Millian — whose role was first reported by the Wall Street Journal and has been confirmed by The Washington Post — were central to the dossier compiled by the former spy, Christopher Steele. While the dossier has not been verified and its claims have been denied by Trump, Steele’s document said that Millian’s assertions had been corroborated by other sources, including in the Russian government and former intelligence sources.

The most explosive allegation that the dossier says originally came from Millian is the claim that Trump had hired prostitutes at the Moscow Ritz-Carlton and that the Kremlin has kept evidence of the encounter.

By his own evolving statements, Sergei Millian is either a shrewd businessman with high-level access to both Trump’s inner circle and the Kremlin, or a bystander unwittingly caught up in a global controversy.

An examination of Millian’s career shows he is a little of both. His case lays bare the challenge facing the FBI as it investigates Russia’s alleged attempts to manipulate the American political system and whether Trump associates participated.

It also illustrates why the Trump administration remains unable to shake the Russia story. While some of the unproven claims attributed in the dossier to Millian are bizarre and outlandish, there are also indications that he had contacts with Trump’s circle.

Millian told several people that during the campaign and presidential transition he was in touch with George Papadopoulos, a campaign foreign policy adviser, according to a person familiar with the matter. Millian is among Papadopoulos’s nearly 240 Facebook friends.

Trump aides vehemently reject Millian’s claims to have had close contact with Trump or high-level access to the president’s company.

Millian did not answer a list of detailed questions about his interactions with Trump and his role in the Steele dossier, instead responding by email with lengthy general defenses of Trump’s election as “God’s will” and complaining that inquiries about his role are evidence of a “witch hunt” and “McCarthyism.”

“Any falsifications, deceit and baseless allegations directed against any US President is damaging to the national security interests of the United States,” he wrote in one email. “Publishing slanderous stories about the President’s decency and offensive material about the first family is malicious propaganda and a threat to the national security in order to destabilize the integrity of the United States of America and stir civil disorder aiming at reducing its political influence in the world.”

(Jason Aldag,Sarah Parnass/The Washington Post)

In late January, Millian appeared on Russian television, where he denied knowing information that could be damaging to Trump. “I want to say that I don’t have any compromising information, neither in Russia nor in the United States, nor could I have,” he said, speaking in Russian. “Without a doubt it is a blatant lie and an effort of some people — it’s definitely a group of people — to portray our president in a bad light using my name.”

The dossier, decried by Trump as “phony stuff” and “fake news” and derided by Russian President Vladi­mir Putin as “rubbish,” consists of a series of reports compiled by Steele over the course of several months before the election.

Millian, identified in different portions of the dossier as “Source D” and “Source E,” is described as a “close associate of Trump.”

In addition to the salacious allegations that gained widespread attention, the dossier attributed other claims to Millian. For instance, Steele wrote that Millian asserted that there was a “well developed conspiracy of cooperation between [Trump] and Russian leadership,” claiming the relationship was managed for Trump by former campaign chairman Paul Manafort. A Manafort spokesman said “every word in the dossier about Paul Manafort is a lie.”

FBI Director James B. Comey, left, and National Security Agency Director Mike Rogers appear before the House Intelligence Committee on March 20. (Matt McClain/The Washington Post)

Some of those who know Millian described him as more of a big-talking schmoozer than a globe-trotting interlocutor. They say he’s a self-promoter with a knack for getting himself on television — like the time he appeared on a 2013 episode of the Bravo reality show “Million Dollar Listing,” where he attempted to broker a sale with a Russian-speaking client who agreed to pay $7 million in cash for a luxury New York unit.

“He’s an opportunist. If he sees an opportunity, he would go after it,” said Tatiana Osipova, who was a neighbor of Millian’s when he lived in Atlanta and who in 2006 helped him found a trade group, the Russian American Chamber of Commerce in the USA. Osipova now lives in St. Petersburg but has remained in touch with Millian. “He’s a fun guy, a smart guy. But always talking. He talks so much s---.”

Millian’s original name was Siarhei Kukuts, but those who know him say he changed it because he wanted something that sounded more elegant. He told ABC News in July that he changed his name to honor his grandmother, whose last name he said was Millianovich. He has also at times gone by the name Sergio Millian.

“My general impression of him was that he just wanted to be important. Nobody really knew what he or the chamber were doing, but he presented himself with grandeur,” said Nadia Diskavets, a New York photographer who was also a founding member of the Russian American Chamber of Commerce but has not been in touch with Millian recently. “So I always took everything he said with a grain of salt.”

Another acquaintance referred to him in a similar way, saying he exaggerated his connections with Trump and with the Russians. “He’s too small of a fish to deal with Russian people,” she said. “They will smell his smallness from miles away.”

Born in Belarus, Millian, 38, attended a university in Minsk. A Russian-language version of his biography that was posted on the Russian American Chamber of Commerce’s website says he studied to be a military translator.

He arrived in the early 2000s as a young, single professional in Atlanta, which has a large ­Russian-speaking community. Friends there said he worked in real estate, and, according to one résumé posted online, he opened a translating business whose clients included the Russian Ministry of Foreign Affairs.

Friends said that Millian founded the Russian American Chamber of Commerce as a way to forge business ties between the United States and Russia and as a personal networking opportunity.

Millian’s affiliation with the group also appears to have boosted his profile in Russia. He hosted events in the United States and abroad on the chamber’s behalf and, after moving to New York, began being interviewed repeatedly by Russian-language news outlets as an expert on U.S.-Russia relations. He traveled to Moscow in 2011 courtesy of a Russian government cultural group later investigated by the FBI for allegedly recruiting spies, though there is no evidence that the inquiry involved Millian.

Millian’s account of his relationship with Trump has shifted over time. As the Republican candidate was rising in the spring of 2016, a time before there was close scrutiny of Trump’s ties to Russia, Millian used his media appearances to describe deep connections with the New York real estate mogul.

He told the Russian state-operated news agency RIA Novosti last April, for instance, that he met Trump at a Miami horse-racing track after “mutual associates” had organized a trip for Trump to Moscow in 2007.

From there, Millian said, he entered into a business arrangement in which he says he helped market a Trump-branded condominium complex in Hollywood, Fla., to international investors, including Russians.

Millian’s description of the Miami event appears to match up with a picture he posted on Facebook that appears to show him posing with Trump and the project’s developer, Jorge Pérez — the only evidence that Millian ever met Trump.

A spokesman for Pérez said his company has no record of paying Millian in connection with the project, and Pérez declined to comment further.

A White House spokeswoman said, “Sergei Millian is one of hundreds of thousands of people the president has had his picture made with, but they do not know one another.”

Millian, however, promoted ties he claimed to hold with Trump’s company.

A 2009 newsletter posted to the website of the Russian American Chamber of Commerce reported that the group had “signed formal agreements” with the Trump Organization and Pérez’s company “to jointly service the Russian clients’ commercial, residential and industrial real estate needs.”

In the interview with RIA Novosti, Millian boasted that when he was in New York, Trump introduced him to his “right-hand man,” Michael Cohen, a longtime Trump adviser — a claim that Cohen has denied.

“He is the chief attorney of Trump, through whom all contracts have to go,” Millian told the Russian news outlet, adding, “I was involved in the signing of a contract” to promote Trump’s real estate projects in Russia.

“You can say that I was their exclusive broker,” Millian continued in Russian. “Back then, in 2007-2008, Russians by the dozens were buying apartments in Trump’s buildings in the U.S.A.”

Asked in the April interview how often he spoke to Trump or his associates, Millian responded: “The last time was several days ago.”

Millian told people last year that he was in touch with Papadopoulos, whom Trump had described in a March 2016 Washington Post editorial board interview as a member of his foreign policy team and an “excellent guy.”

Papadopoulos received attention during the campaign largely because of reports that he had exaggerated his résumé and cited among his accomplishments that he had participated in a Model United Nations program for college and graduate students.

But, according to foreign news reports and officials, he conducted a number of high-level meetings last year and presented himself as a representative of the Trump campaign. He told a group of researchers in Israel that Trump saw Putin as “a responsible actor and potential partner,” according to a column in the Jerusalem Post, while later he met with a British Foreign Office representative in London, an embassy spokesman said. He also criticized U.S. sanctions on Russia in an interview with the Russian news outlet Interfax.

Papadopoulos did not respond to questions about contacts with Millian. But Papadopoulos said by email that his public comments during the campaign reflected his own opinions and that some of his energy policy views run counter to Russian interests. “No one from the campaign ever directed me to discuss ‘talking points,’ ” he said. In a separate email, he accused The Post of relying on “innuendo” and “unsubstantiated claims by irrelevant sources.”

Neither Millian nor a White House spokeswoman responded to questions about Papadopoulos. The person familiar with the contacts, who spoke on the condition of anonymity, did not provide details.

Over the summer, as Trump prepared to accept the Republican presidential nomination, Millian traveled to Russia. He posted pictures on his Facebook page showing that he attended a ­Russian government-sponsored summit in St. Petersburg in June. One photograph shows him with Russia’s minister for energy. Another shows him chatting with Russian aluminum magnate Oleg Deripaska, who is close to Putin. A spokeswoman for Deripaska declined to comment. A spokesman for the Russian Embassy did not respond to questions about Millian.

Later in the summer, Millian continued boasting of his Trump connections.

He told ABC News that he had been the “official broker” for the Trump-branded condo building and described Trump’s affinity for working with Russians. He pointed to “hundreds of millions of dollars that [Trump] received from interactions with Russian businessmen.”

Millian added that Trump “likes Russia because he likes beautiful Russian ladies — talking to them, of course. And he likes to be able to make lots of money with Russians.”

Millian told ABC that he was “absolutely not” involved with Russian intelligence. But when asked whether he had heard rumors to that effect, Millian replied, “Yes, of course.”

Millian also said that, at times, he talked about U.S. politics with top Russian officials. “Usually if I meet top people in the Russian government, they invite me, say, to the Kremlin for the reception, of course I have a chance to talk to some presidential advisers and some top people,” Millian said.

While Cohen has said he has never met Millian, the two did interact last year over Twitter. Millian was, for a time, one of about 100 people that Cohen followed and they tweeted at each other on one occasion in August after Cohen appeared on television.

Cohen later unfollowed Millian, telling The Post that he had mistakenly thought Millian was related to a Trump Organization employee with a similar last name.

“He is a total phony,” Cohen said in an interview. “Anything coming out of this individual’s mouth is inaccurate and purely part of some deranged interest in having his name in the newspaper.”

Cohen said he did not believe Trump was in Russia in 2007, as Millian claimed in April.

Cohen said it was possible that, like other brokers in Florida, Millian might have attempted to sell units at Trump Hollywood. But, he said, Millian never held an exclusive deal at the project or any contract with the Trump Organization.

Speaking with The Post over the phone from his New York office in a January interview, Cohen also read aloud from a lengthy email he said Millian had sent him shortly before the election that contradicted his earlier public statements.

“I met Mr. Trump once, long time ago, in 2008, pretty much for a photo opportunity and a brief talk as part of my marketing work for Trump Hollywood, after my brokering service was signed. Now, to say that I have substantial ties is total nonsense,” Cohen said, reading from an email he said Millian wrote after media coverage that mentioned him.

In the email, Millian suggested holding a news conference to clear up the matter, Cohen said. Cohen said he rejected the idea, accusing Millian via email of “seeking media attention off of this false narrative of a Trump-Russia alliance” despite having met Trump only one time, “for a 10 second photo op.”

Cohen, who left his job at the Trump Organization in January to become Trump’s personal attorney, said this month that he could not release a copy of Millian’s email because he no longer has access to the company’s email system.

In South Florida, where Millian claimed to have had a contract to sell units at Trump Hollywood, there is little evidence that he played a major role.

Daniel Lebensohn, whose company BH3 took over for the Related Group in 2010 after Pérez’s company struggled to complete the project, said his company’s records show no sign that Millian sold any units in the building.

Two Florida-based real estate brokers who specialize in the Russian market and have sold units in Trump Hollywood were equally mystified.

“I’ve never heard of him,” said Olga Mirer, who has traveled back and forth to Russia over the past decade brokering deals at Trump Hollywood and other Florida buildings.

Miss Universe 2013, Gabriela Isler of Venezuela, left, and pageant owner Donald Trump point to each other while posing for a photo after the 2013 Miss Universe pageant in Moscow on Nov. 9, 2013. (Ivan Sekretarev/AP)

Despite the Trump team’s efforts to distance the president from Millian, the dossier source nevertheless attended Trump’s inauguration in January.

He posted photos of himself on Facebook attending VIP events for supporters, including one in which he posed in front of the podium at a reception for Trump chief of staff Reince Priebus at Trump’s Washington hotel. A White House official did not address a question about Millian’s attendance.

Alice Crites in Washington and David Filipov in Moscow contributed to this report.